MXPA00005652A - Interlayer structure for laminated glass - Google Patents

Abstract

The present invention relates to a multilayer aligned interlocked polyvinyl butryal composite structure which has good properties as a component in glass laminate structures, especially in those structures needing thick (greater than 0.76 mm) interlayers of PVB. The multilayer structures is produced by a process which uses two or more rollers containing plasticized PVB sheeting which are aligned and interlocked by simultaneous unwinding of the layers at set line speeds, temperatures and unwinding tensions.

Description

STRUCTURE OF INTERCAPAS FOR LAMINATED GLASS AND THE PROCESS FOR THE PRODUCTION OF THE STRUCTURE OF INTERCAPAS Field of the Invention The present invention relates to an improved interlayer product for the preparation of laminated safety glass. More particularly, the invention relates to an interlayer product for laminated safety glass where the multiple layers of the interlayer interlayer film have the desired thickness properties and the fracture melting pattern of the surface are combined to meet the needs specific functional Background of the Invention - In laminated safety glasses used for window panes for buildings and the like, it is common for the laminator to use thicker interlayers than those typically used in automotive applications, which are nominally 0.76 mm (30 mils) thick, or combine Ref: 120074 multiple layers of 0.76 mm (30 mils) in interlayers to execute a coarse product to increase its structural properties. This is not, however, a description of the processing or "use of crosslinked layers (at least two) of polyvinyl butyral containing film between the glass layers.

The extrusion process for the production of a thick interlayer, which is greater than 0.76 mm (30 mils), requires high ranges of total throughput and low line speeds, and results in deficiencies in dimensional stability, such as shrinkage, difficulties in the winding and cutting, and additional manufacturing transitions and problems in generating the melting fracture surface pattern necessary to properly desaerear when the glass / interlayer construction is laminated.

It has now been found that by combining, in a controlled winding process, at least two interlayer layers of varying thickness with the desired melt fracture surface pattern in such a manner that sufficient cross-linking of the sheets occurs, excellent sheets of glass. When they are not open, the sheets can be handled as an integral unit but are not intimately joined so that the air can separate them between the layers that can result in unacceptable laminated glass.

U.S. Patent No. 4,230,771 discloses polyvinyl butyral laminates with plasticizer of tet raet ilenglicol di-N-heptanoate. This patent specifically describes sheets of polyvinyl butyral and plasticizer that are formed into a single sheet of 0.80 mm laminated between two layers of glass. This is not a teaching of multiple layers of polyvinyl butyral of any thickness.

U.S. Patent No. 4,292,372 discloses sheets of polyvinyl butyral bleached with a hydrolyzable ester having a low concentration of acid. This reference describes a sheet of 0.03 inches (0.000762cm) that is laminated between two sheets of glass.

U.S. Patent No. 4,297,262 discloses piles of polyvinyl butyral with tetraethylene glycol di-n-heptanoate. The reference describes the use of a single sheet of such material sandwiched between the glass layers to provide a composition of rupture-resistant material.

European Patent EP 0 710 545 describes a multi-layered product for laminated glass wherein the multi-layered elements are first intimately bonded and then the desired pattern is embossed on the outer surfaces. In addition, it is pointed out that if the outermost layer does not thicken enough, minor ruptures occur on the inner side that begin to distort the optics. The layers may consist of different polyvinyl butyral plasticized resin films having different average polymerization grades (delta 300-4,500) and / or have different plasticization percentages or content (delta = 5 parts by weight up to 50 parts by weight per weight). 100 parts of the resin that is made in each interlayer). Other different interlayers include films with different glass transition temperatures, etc.

In the present invention, even with the pattern on both surfaces of the -international face, no optical distortion is observed.

The European Patent, EP 0 465 698 A1, describes a process for applying a bond integrally to two paper networks.

Brief description of the invention.

In the process of the present invention, two or more rolls of sheets comprising polyvinyl butyral as the primary component with plasticizers as the secondary component as interlayer and / or interparty material are not woven simultaneously and rewound under controlled tension, speed of line and temperature so that the edges of the respective layers are aligned and the formation of the roll is normal, the tension of the respective sheets is equal, the thickness is maintained and the entrapment of the air is minimized. The resulting product is used to produce laminated safety glass with a thick interlayer construction.

The present invention therefore comprises a multilayer composition structure, comprising, namely, (a) a first layer of polyvinyl butyral plasticizer; Y (b) one or more additional layers of polyvinyl butyral plasticizer wherein the layers (a) and (b) are crosslinked. This multilayer composition structure is useful as a material that is sandwiched between multiple layers or layers of glass to form shatter resistant glass composition structures for use in automobile windows, commercial windows and the like. More particularly, the present invention comprises said multilayer composition structure wherein the first layer and one or more additional layers are equal to or greater than 0.38 mm per layer. The preferred system or the preferred polyvinyl butyral multilayer plasticizing layers have either the same degree of polymerization of the PVB or the same percentage of plasticizer in each layer relative to the weight of the PVB in which the layer or both have the same degree of polymerization and the same percentage of plasticizer.

The present invention also relates to or comprises a process for producing the multilayer composite structure described above by, (i) unrolling a first layer of polyvinyl butyral plasticizer from a first roll (! ') at a line speed of 10-50 meters / minute at a temperature of 5-35 ° C and at an uncoiling tension of 4-5 ° C. 70 Ne tons meter / meter of sheet width to form a first network; (ii) simultaneously unrolling at least one additional layer of polyvinyl butyral plasticizer from a second roll (1) at a line speed of 10-50 meters / minute and at a temperature of 5-35 ° C and at an unwinding tension of 4 -45 Newtons meter / meter blade width to form at least one second network; and (iii) combining the layers (i) and (ü) in a clearance roll (5) to form an aligned cross-linked multilayer composition structure.

In this way, PVB sheets between 15 and 60 mils (.38 mm up to 1.52 mm) can be used with tension varying accordingly. The process may further comprise unrolling a polyolefin protective sheet from an unwound roll (1") at a tension of 2 to 5 Newtons meter / meter simultaneously with the first and second rolls and, in step (3) , combining the layers (i) and (ii) with the protective sheet as the top layer in the clearance roll to form an aligned cross-linked multilayer composition structure having a polyolefin protective sheet.

The present invention also relates to a multilayer composition structure produced from the process (s) recited above.

The present invention also relates to a multilayer composition structure, comprising, namely, (a) at least one layer of glass; (b) at least two crosslinked layers of polyvinyl butyral plasticizer; Y (c) at least one additional glass layer and refers to said multilayer composition structure produced by (i) forming at least two crosslinked layers of polyvinyl butyral plasticizer and (ii) sandwiching at least two layers crosslinked between the glass layers ( a) and (b) where the layers crosslinked before step (ii) are not exposed to ambient temperatures greater than 10 ° C.

Brief Description of the Drawings.

Figure 1 is a side elevational view of the interleaving process showing the blade path for the combination of two interlayer rolls; and Figure 2 is a side elevational view of the interleaving process showing the sheet path for the combination of two interlayer rolls plus a separate interlayer of three interlayer rolls.

Detailed description of the invention.

In the glass laminate industry, especially in architectural applications, it is often the case that multiple layers of polyvinyl butyral are used leafed in interlayers to perform specific structural properties. The final thickness of the multiple layers depends completely on the desired strength properties.

The polyvinyl butyral interlayer sheet can be produced by the extrusion process well known in the art. Such a process is described in, for example, US Patents Nos. 4,230,771; 4,292,372; 4,297,262; 3,679,788; 4,161,565 and 5,151,234 which are incorporated herein by reference. This laminate typically contains a large percentage of plasticizer, for example, about 30-50 parts by weight per 100 parts by weight of polyvinyl butyral are used. Suitable plasticizers for this purpose include, but are not limited to, dibutyl sebacate, triethylene glycol di (2-ethyl butyrate), triethylene glycol di (2-ethyl hexanoate), di (beta-butoxyethyl) adipate, dihexyl adipate, triethylene. glycol di-heptanoate, tetraethylene glycol diheptanoate, tetraethylene glycol di (2-ethyl hexanoate), and butylbenzyl phthalate. The preferred plasticizer is the tet raet i lengl icol di-heptanoate, the preferred range or amount of plasticizer is 35-45 parts by weight per 100 parts by weight of polyvinyl butyral.

Suitable polyvinyl butyrals for the manufacture of sheet sheets also include, for example, those containing, in addition to polyvinyl butyral units, from 17-25% by weight, preferably 20.5-23.5 by weight percent, of alcohol units of polyvinyl, and less than 5 weight percent of polyvinyl acetate units. The term polyvinyl butyral in a layer or sheet described herein also includes those polymers having these additional monomer units.

Suitable glass layers for forming the multilayer composition structures having the crosslinked multilayers of the invention are obtained here and / or formed from known sources. This multilayer glass structure is then used in automobiles or buildings or the like.

The shape created with relief on the surface of the leaflet consists of multitudes of notches and discontinuous discontinuous protrusions disoriented (randomly) and roughness, R, of the shape of relief on the surface of the sheet can be adjusted to a value in the range of 15-70 μm, which is appropriate for use in the manufacture of laminated glass, or more preferably, at a value in the range of 20-50 μm. In this case, the relief is really a fusion fracture pattern and not a mechanical relief with the rolls.

However, these are disadvantages to produce a substantially thicker interlayer of 0.76 mm (30 millimeters), the standard for safe glass applications in automobiles, by the extrusion method. These include high total performance ranges but low line speeds, deficient in dimensional stability, such as shrinkage, difficult winding, consumed transitions time and waste generation, and, more particularly, difficulty in generating the surface pattern of fusion fracture necessary for the appropriate desensitization in glass lamination processes.

Other well-documented methods in the art used to create the surface pattern in an interlayer to make safety glass laminate include embossing and extrusion through the use of rows with saw lips. All these add complexity and cost to the extrusion processes.

The polyvinyl butyral rough surfaces exposed in interlayers are typically measured with a surface profilometer. The Rz parameter, the average peak height of ten points, and Sm, the average space between the peaks, as defined in the American National Standard B46.1-1985, are commonly used to characterize the free of roughness. The higher the value Rz of the roughness of the pattern and the higher the value of Sm, the smaller the distance between the peaks per unit.

A defect in the lamination of vinyl, small, is removed in the vinyl of the edge of the glass and this causes an excessive decrease of the vinyl before its union to the glass. In the finished product, delamination can begin with exposure and this is unacceptable.

It has now been shown that the polyvinyl butyral plasticizer interlayer can be produced by the combination of multiple slimming layers in a controlled winding operation to produce a crosslinked multilayer PVB skim as useful as glass layers between the interlayer. Using individual layers with a surface pattern without asperities for the specific laminated application used as a roll pass, vacuum bag or vacuum ring, the final composition can cover all the needs of the laminated glass industry without sacrificing the processes and properties as noted above.

When the multiple layers of the melt fracture pattern polyvinyl butyral interlayer are combined in the process described in Figure 1, the resulting composition structure surprisingly behaves as an integral unit when used to make laminated glass. The light bonding of the layers is the result of a mechanical assurance of the random melting point fracture surface pattern.

• The term "crisscrossed" means the union between two or more layers of PVB sheets that are stamped enough to allow uniform unwinding of the composition, ease of cutting, and positioning in the glass, but not to intimate the joint in the which air can not be easily removed by methods typically used in the laminated glass industry. This unexpected description is important since open separation makes handling difficult and air separation can result in bubbles in the sheet that make it useless. The peaks and valleys of the opposed biased PVB sheets are aligned and mallated in such a way that the leaves behave like a leaf are the defects that are normally associated with the leaves of a thickness greater than 0.76 mm. The term "interlaced or crisscrossed" also means that the plastified PVB interlayers described herein are produced using the processes of the invention. In this case, for such products produced by these processes, they do not require or require two or more PVB ply layers to be identical in degree of polymerization and / or percentage of pipification for the compositions or resins such as those described in EP. 0 710 545 Al or otherwise, said layers produced according to the processes described herein can be used here. The interlayer production process as claimed herein is exactly in contrast to the compression and block method as described in the earlier patent application EP 0 710 545 A1. The additional steps performed after the process of this invention can be used to simulating this block method such as that performed for intimate bonding (not crosslinking) by heating the product produced by the process of this invention at temperatures greater than 10 ° C.

The process of the present invention is generally carried out in accordance with the schematic drawings in Figure 1 and Figure 2.

To carry out the process of the present invention in accordance with Figure 1, the rollers (or rolls) can be combined and placed in positions 1 and 1 'without being rolled up. It has been shown that controlling tension without coiling, the line speed and the temperatures provided for an optimal alignment, the roll is formed, the thickness is controlled and the air trapped from the loss of leafing is minimized. The line speeds are between 10-50 meters / minute (21.8-164 feet / minute), preferably 25-35 meters / minute (82-115 feet / minute). The leafing temperature is maintained between 5-35 ° C (41-95 ° F), preferably 10-20 ° C (50-68 ° C).

The alignment and roll formation are also increased by having the combined webs joined together by a minimum amount of travel of the machine, preferably only before winding.

The tension in the upper unwind roll is adjusted during the unwinding process as a function of roll diameter, thickness and width. Using a diameter sensor 2 as a guide, the brake handle 3 is adjusted to provide the desired tension. This tension is controlled between 4-45 Newtons meter / meter of the blade width (.07 to .84 pounds of force per foot / inch of the width of the blade) depending on the diameter of the unwinding roll.

The tension in the lower unrolled roller is automatically adjusted by the brake handle 3 'using the feedback of the full cell 4. The tension in the lower unwinding is controlled to be between 4-70 Newtons meter / meter of the width of the sheet ( 0.7 to 1.3 pounds of force foot / inch blade width).

The sheets of nets are combined in the handling of coiling 5.

To carry out the process of the present invention in accordance with Figure 2, the rolls are combined and placed in the unwrapped positions 1, 1 'and 1". Tension and temperature control should be maintained as previously described.

The tension in the third roller is adjusted during the unwinding process as a function of the roll diameter, thickness and width of the roll using the diameter sensor 2 'as a guide for adjusting the brake handle 3". When using intersheet material, the tensions in the third roll are controlled between 2 and 5 N meter / meter of sheet width.

The use of the curved expanded roll "Poliband" 6 greatly facilitates the operation when using thin interleaving material.

The crosslinked multilayer plasticising PVB skim is then sandwiched between the glass layers in accordance with conventional processes to form a multilayer glass composition structure that is suitable for automotive applications as well as industrial and / or commercial windows or glass structures.

The invention is further illustrated by the following examples.

Test Methods.

Short Vinyl Test Following the use of an autoclave, the edges of the laminate are visually inspected for the presence of short vinyl. That is, a shrinkage of the vinyl inside the laminate. If any shrinkage is found, insert a thin metal rule into the gap until it sits against the polyvinyl butyral. The depth of penetration is then measured in millimeters and the longest value measured is reported as short vinyl.

Examples Example 1 Two rolls of 0.76 mm (30 mils) of thick polyvinyl butyral interlayers of 2 meters wide (PVB, 23% Alcohol PV, <5% PV Acetate) and with 39 parts of tetraethylene glycol diheptanoate per 100 parts of resin ) with a Rz value of 24.7 micrometers and an Sm value of 43.3 micrometers, were combined in the process described in Figure 1. The line speed was 30 metres / min (98.4 ft / min) and the leafing temperature was of 15 ° C (59 ° F). The resulting roll was maintained at typical storage temperatures, < 10 ° C (< 50 ° F), to prevent blockage of the wrapper in the roll. The tension in roll 1 'was 9.5 to 35 N M / M and in roll 1 from 9 to 22 N M / M.

When the material was unrolled, the layers were found to be sufficiently joined to allow handling and placement in the glass. The interleaved construction of the glass / 2-ply polyvinyl butylated glass / interlayer was heated in an oven to 60 ° C (140 ° F) and was then passed through the pressure roller at 1 meter / minute (3.28 ft / minute). The quality of the airless was excellent as judged by the almost complete clarity of the construction after the pressure.

Following the autoclave use under standard conditions, the sheets were inspected and judged visually to be satisfactory without bubbles or short vinyl.

Comparative Example A.

A 1.52 mm (60 mil) roll of coarse polyvinyl butyral interlayers (2 meters wide with the same composition as in Example 1) produced with a Rz value of 30.1 microns and an Sm value of 30.0 microns, typically by extrusion of thick interlayer, unrolled. No handling problems were found during the saving process. Interleaved glass / polyvinyl butyral laminated interlayer / glass construction required 70 ° C (158 ° F) furnace temperature to perform almost the similar clarity of Example 1 at a rate of 1 meter / minute (3.28 feet / meter) .

Under these processing conditions, the sheets still exhibited some trapped air clouds and 2-3 mm (80-120 millimeters) of short vinyl flush with the edges.

Following the use of autoclave under standard conditions, the sheets were judged unacceptably with bubbles and short vinyl still present.

Comparative Example B Two rolls of 0.76 mm (30 millimeters) thick polyvinyl butyral interleaved (2 meters wide with the same composition as in Example 1) produced with a Rz value of 24.5 microns and an Sm value of 39.7 microns were combined in the process described in Figure 2 using a 0.025 mm (0.001 mil) polyethylene interleaved between the wrap. The line speed was 30 meters / minute (98.4 feet / minutes) and the leafing temperature was 15 ° C (59 ° F) with identical voltages to those of Example 1 and including a roll tension of 2- interleaved 5 NM / M. the resulting roll was purposely kept at ambient temperatures > 10 ° C (> 50 ° C) to force the intimate bonding of the two PVB layers to stimulate the stacking of the PVB layers as previously described in the art.

When the material was unrolled, it was found that the layers were more intimately bonded than in Example 1 and more difficult to remove the film. These did not handle or place problems in the save. Interleaved glass / polyvinyl butyral laminated interlayer / glass construction was heated in an oven to 61 ° C (142 ° F) and then passed through pressure rollers at 1 meter / minute (3.28 feet / minute), some air trapped between the layers became evident otherwise the clarity of the construction after the pressure was similar to that of Example 1.

Following the use of autoclave under standard conditions, the sheets were judged unacceptably with bubbles and short vinyl still present indicating that the intimate junction (non-crosslinked junction) occurred. This example clearly demonstrates that the claimed product produced by the claimed process provides good physical properties without defects even for plasticized PVB composition which are identical, for example, having the same degree of polymerization and the same percentage of plasticizer. The claimed process is therefore much more efficient since the artisan does not have to vary the PVB leafing to arrive at an appropriate conventional thickness or thick multilayer PVB interlayers.

It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects to which it refers.

Having described the invention as above, the content of the following is claimed as property.

Claims (18)

Claims

1. A multilayer composition structure, characterized in that it comprises, namely, (a) a first layer of polyvinyl butyral plasticizer; Y (b) one or more additional layers of polyvinyl butyral plasticizer wherein the layers (a) and (b) are crosslinked.

2. The multilayer composition structure according to claim 1, characterized in that the first layer and one or more additional layers are equal to or greater than 0.38 mm per layer.

3. The multilayer composition structure according to claim 1, characterized in that the polyvinyl butyral plasticizer in (a) and (b) has the same degree of polymerization.

4. The multilayer composition structure according to claim 1, characterized in that the polyvinyl butyral plasticizer in (a) and (b) has the same percentage of plasticizer.

5. A process for the production of an aligned cross-linked multilayer composition structure, characterized in that it comprises, (i) unrolling a first layer of polyvinyl butyral plasticizer from a first roller at a line speed of 10-50 meters / minute at a temperature of 5-35 ° C and at an unwinding tension of 4-70 Newtons meter / meter of sheet width to form a first network; (ii) simultaneously unrolling at least one additional layer of polyvinyl butyral from a second roller at a line speed of 10-50 meters / minute and at a temperature of 5-35 ° C and at an uncoiling tension from 4-45 Newtons meter / meter blade width to form at least one second network; Y (iii) combining the layers (i) and (ii) on a take-off roller to form an aligned cross-linked multilayer structure.

6. The process according to claim 5, characterized in that the first layer and at least one additional layer are equal to or greater than 0.38 mm in thickness.

7. The process according to claim 5, characterized in that it further comprises unrolling a polyolefin protective sheet from an unrolled roll at a tension of 2 to 5 Newtons meter / meter of sheet width simultaneously with the first and second rolls and, in step (3), combining the layers (i) and (ii) with the protective sheet as the top layer on the clearance roll to form an aligned cross-linked multilayer composition structure having a polyolefin protective sheet.

8. The process according to claim 7, characterized in that it further comprises maintaining the multilayer composition structure crosslinked at a temperature of equal to or less than 10 ° C.

9. A multilayer composition structure, characterized in that it is produced in accordance with the process according to claims 5, 6, 7 or 8.

10. A multilayer composition structure, characterized in that it comprises, namely, (a) at least one layer of glass; (b) at least two crosslinked layers of polyvinyl butyral plasticizer; Y (c) at least one additional glass layer

11. The multilayer composition structure according to claim 10, characterized in that at least two crosslinked layers are equal to or greater than 0.76 mm in thickness.

12. The multi-layer composition structure according to claim 10, characterized in that each cross-linked layer is 0.76 mm thick.

13. The multilayer composition structure according to claim 10, characterized in that the plasticizer in the layers of polyvinyl butyral plasticizer is present in a weight percentage of 30-50 parts by weight per 100 parts by weight of the polyvinyl butyral.

14. The multilayer composition structure according to claim 13, characterized in that the weight percentage of the plasticizer in each layer is identical.

15. The multilayer composition structure according to claim 10, characterized in that the plasticizer is selected from dibutyl sebacate, triethylene glycol di (2-ethyl butyrate), triethylene glycol di (2-ethyl hexanoate), di (beta-butoxyethyl) adipate, diethyl adipate, triethylene glycol di-heptanoate, tetraethylene glycol dihept anoat, tetraethylene glycol di (2-ethyl hexanoate), and butylbenzyl phthalate.

16. The multilayer composition structure according to claim 10, characterized in that the polyvinyl butyral contains, in addition to the polyvinyl butyral units, from 17-25% by weight of polyvinyl alcohol units and less than 5% by weight of acetate units of polyvinyl.

17. A process for the production of a multilayer composition structure according to claim 10, characterized in that it comprises, (i) obtaining a crosslinked PVB plasticizer and (i i) interleaving the crosslinked PVB ticking country between at least two layers of glass.

18. A car or building characterized in that it has the multilayer composition structure according to claim 10.